Liquid compositions for personal washing applications have been known. Such compositions include hand washing liquids usually dispensed from bottles provided with a hand pump which is actuated by pressing with the hand. Such kind of hand washing liquids are also dispensed in public places like bathrooms in airports, hotels, restaurants and offices. Other personal cleaning liquids include facewash liquids, bodywash liquids, shampoos and hair conditioners.
Such compositions are used not only to clean the surface of the body to give the consumer of feeling of being clean of dust, sebum, and sweat but also give the consumer a satisfaction of having disinfected the surface to be free of disease causing germs. Liquid forms of such compositions are known for personal care. Such compositions include antimicrobial actives that specifically target microorganisms like bacteria and virus to either kill or inactive them.
Sanitizing and disinfecting soap compositions comprising chlorine-based antimicrobial agent such as triclosan are known. Such compositions require rather long contact time to provide efficacious antimicrobial action. In practice, users, in particular children, do not spend long time in cleaning and as a result, cleaning with such compositions does not provide adequate prevention from surface or topical infection or adequate protection against diseases. The user, in spite of cleaning hands, is likely to have skin with relatively inadequate bacterial removal and may cause contamination of further animate and/or inanimate surfaces that may lead to spreading of pathogens and consequent diseases. Users in general and children in particular who wash contaminated hands before meals with slow-acting antimicrobial compositions for relatively short time are at risk of contacting diseases. These short time scales of cleaning action are ineffective in providing the desired benefit since most known antimicrobials commonly used in such products take several hours to provide the desired kill of microbes.
Therefore, the present applicant realized the need for providing a composition that gives relatively more efficacious antimicrobial action when cleaning period is relatively small, typically about 5 minutes or less, preferably lesser than 2 minutes and in many cases less than one minute or sometimes as low as 15 seconds or lesser. They have, in a prior patent application published as WO2010046238 disclosed a novel combination of thymol and terpineol that interact synergistically to enable fast antimicrobial action in less than about 15 seconds. The present inventors have found that inclusion of selected di or tricarboxylic acid or a salt thereof, when combined with thymol or terpineol provide similar synergistic antimicrobial action in a rapid fashion and such efficacy is obtained at much lower concentrations of thymol and/or terpineol. This invention has the advantage that essential oil actives like terpineol and thymol have a strong medicinal odour which is not liked by some consumers and it is advantageous to include thymol and terpineol at lower concentrations while ensuring the same efficient anti-microbial action. Further, it has been found by way of the present invention that inclusion of select anionic surfactants aids in further enhanced antimicrobial efficacy.
Liquid personal cleaning compositions are known. US2008045491 (Fitchmun) discloses a non-toxic antimicrobial surface sanitizer composition comprising a water-miscible alcohol, water, a weak acid and a multivalent cation (e.g. metal ion or metal compound). The composition may also include one or more of an emollient, oxidative agent, humectant, lubricant, plant-derived alkene, antimicrobial component or plant-derived essential oil can be formulated as solutions for sanitizing hard surfaces such as countertops and floors, or as solutions/gels for application to animal skin.
The above publication utilizes the well known antimicrobial efficacy of alcohol which is much stronger than most other known antimicrobial actives. Many consumers do not prefer to use products that utilize alcohol as they consider it as harsh on the skin and so it is desirable to develop new combination of actives that provide similar or better anti-microbial efficacy in much rapid time frame while utilizing actives that are considered mild on skin.
US2006093570 (Reckitt Benckiser) describes a surface treatment composition, preferably for personal use, comprising at least one surfactant and at least two different organic acids and/or salts or organic acids, and wherein the total concentration of the organic acids and/or salts in the composition is at least 0.5 percent (w/v). The invention further extends to a method of treating a surface, preferably hair or skin, to remove dirt and to remove or inhibit microbial growth.
The patent publication cited above does not address the problem of slow-acting antimicrobial composition, nor disclose the synergistic combination of actives disclosed and claimed in the present invention for the fast acting antimicrobial action in cleaning and disinfecting skin and/or other keratinous substrates of humans and/or animals.
It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.
Another object of the present invention is to provide a liquid personal care cleaning and disinfecting composition that has relatively fast antimicrobial action.